Portable information device

ABSTRACT

A portable information device is capable of securing the appearance quality or the durability of products while having a foldable configuration. The portable information device has a backbone member provided throughout and between the inner surface of one edge portion of a first chassis member and the inner surface of one edge portion of a second chassis member so as to cover a gap between the one edge portion of the first chassis member and the one edge portion of the second chassis member connected by a hinge mechanisms. The backbone member is held between the inner surfaces of the first chassis member and the second chassis member and the rear surfaces of the hinge mechanisms disposed on the inner surfaces, and is slidably provided between the inner surface of at least one of the first chassis member and the second chassis member and the rear surface of the hinge mechanism disposed on the one inner surface of the at least one of the first chassis member and the second chassis member.

FIELD OF THE INVENTION

The present invention relates to a portable information device providedwith a foldable display on the inner sides of a pair of foldable chassismembers.

BACKGROUND OF THE INVENTION

In recent years, portable information devices, such as a tablet PC and asmartphone having a touch panel type liquid crystal display and nothaving a physical keyboard, have rapidly spread. The display of thiskind of portable information device has been desired to be large in usebut has been desired to be miniaturized in carrying. Then, a portableinformation device has been proposed in which not only a chassis but adisplay is configured so as to be foldable by the use of a flexibledisplay, such as organic EL (Electro Luminescence) (for example, seePatent Document 1).

[Patent Document 1] Japanese Patent Application Laid-Open No.2014-216025

SUMMARY OF THE INVENTION

As a chassis of the above-described folding structure, a configurationof connecting adjacent edge portions between a pair of chassis membersarranged side by side on the right side and the left side by a hingemechanism is mentioned, for example. However, with this configuration,when the pair of chassis members is closed into a double-folded state, agap is generated between edge portions on the hinge sides of the chassismembers. Then, internal elements are exposed from the gap, which hasposed problems in the appearance quality, durability, and the like ofproducts.

The present invention has been made considering the problems of theformer technique described above. It is an object of the presentinvention to provide a portable information device capable of securingthe appearance quality or the durability of products while having afoldable configuration.

A portable information device according to the present invention has afirst chassis member and a second chassis member foldably connected bythe connection of one edge portions disposed adjacent to each other by ahinge mechanism, a display which is provided over inner surfaces of thefirst chassis member and the second chassis member and which is foldableinto a double-folded state, and a backbone member provided throughoutand between the inner surface of the one edge portion of the firstchassis member and the inner surface of the one edge portion of thesecond chassis member so as to cover a gap between the one edge portionof the first chassis member and the one edge portion of the secondchassis member connected by the hinge mechanism, in which the backbonemember is held between the inner surfaces of the first chassis memberand the second chassis member, and the rear surfaces of the hingemechanisms disposed on the inner surfaces, and is slidably providedbetween the inner surface of at least one of the first chassis memberand the second chassis member and a rear surface of the hinge mechanismdisposed on the inner surface of the at least one of the first chassismember and the second chassis member.

A configuration may be acceptable in which the hinge mechanism has afirst hinge chassis fixed on the inner surface of the first chassismember, a second hinge chassis fixed on the inner surface of the secondchassis member, and a hinge shaft rotatably connecting the first hingechassis and the second hinge chassis, in which the first hinge chassisand the second hinge chassis each have a recessed portion communicatingwith each other on rear surface sides thereof, and the backbone memberis disposed in the recessed portions.

A configuration may be acceptable in which the backbone member isprovided to the inner surface of the one edge portion of the firstchassis member so as to be slidable in a direction from the secondchassis member to the first chassis member along the inner surface, andis non-slidably fixed to the inner surface of the one edge portion ofthe second chassis member.

A configuration may be acceptable in which the hinge mechanism isdisposed at each of both end portions in the longitudinal direction ofthe one edge portions in the first chassis member and the second chassismember.

A configuration may be acceptable in which the hinge mechanism has thefirst hinge chassis fixed on the inner surface of the first chassismember, the second hinge chassis fixed on the inner surface of thesecond chassis member, and the hinge shaft rotatably connecting thefirst hinge chassis and the second hinge chassis, the first hingechassis is held between the inner surface of the first chassis memberand a wall portion raised from the inner surface of the first chassismember, and the second hinge chassis is held between the inner surfaceof the second chassis member and a wall portion raised from the innersurface of the second chassis member.

A configuration may be acceptable in which the hinge mechanism isdisposed at each of both end portions in the longitudinal direction ofthe one edge portions in the first chassis member and the second chassismember, the wall portions of the first hinge chassis and the secondhinge chassis each form side walls of the portable information device,and the first hinge chassis and the second hinge chassis are engagedwith the recessed portions formed in the inner wall surfaces of the wallportions.

A configuration may be acceptable in which the hinge mechanism isdisposed at each of both end portions in the longitudinal direction ofthe one edge portions in the first chassis member and the second chassismember, each of the hinge mechanisms is provided at a position locatedon the outside of the outer shape of the display, each hinge mechanismhas a first hinge chassis fixed on the inner surface of the firstchassis member, a second hinge chassis fixed on the inner surface of thesecond chassis member, and a hinge shaft rotatably connecting the firsthinge chassis and the second hinge chassis, and at least a portion otherthan a bending region corresponding to the backbone member of thedisplay is positioned and fixed to the first chassis member and thesecond chassis member, and the surface of the display and the axialcenter of the hinge shaft are disposed on the same plane in a statewhere the first chassis member and the second chassis member are openedinto a flat shape.

A portable information device according to the present invention has afirst chassis member and a second chassis member foldably connected bythe connection of one edge portions disposed adjacent to each other by ahinge mechanism and a display which is provided over inner surfaces ofthe first chassis member and the second chassis member and which isfoldable into a double-folded state, in which the hinge mechanism isdisposed at each of both end portions in the longitudinal direction ofthe one edge portions in the first chassis member and the second chassismember, each hinge mechanism is provided at a position located on theoutside of the outer shape of the display, each hinge mechanism has afirst hinge chassis fixed on the inner surface of the first chassismember, a second hinge chassis fixed on the inner surface of the secondchassis member, and a hinge shaft rotatably connecting the first hingechassis and the second hinge chassis, the display is positioned andfixed to the first chassis member and the second chassis member, and thesurface of the display and the axial center of the hinge shaft aredisposed on the same plane in a state where the first chassis member andthe second chassis member are opened into a flat shape.

A configuration may be acceptable in which each hinge mechanism has afirst arm, one end portion of which is rotatably connected to the firsthinge chassis through a first hinge shaft and the other end portion ofwhich is rotatably connected to the second hinge chassis through asecond hinge shaft and a second arm, one end portion of which isrotatably connected to the second hinge chassis through a third hingeshaft and the other end portion of which is rotatably connected to thefirst hinge chassis through a fourth hinge shaft; and the surface of thedisplay and the axial centers of the first hinge shaft, the second hingeshaft, the third hinge shaft, and the fourth hinge shaft are disposed onthe same plane in a state where the first chassis member and the secondchassis member are opened into a flat shape.

The present invention can secure the appearance quality or thedurability of products can be secured although having a foldableconfiguration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a state where a portableinformation device according to one embodiment of the present inventionis closed into a storage form.

FIG. 2 is a perspective view schematically illustrating a state wherethe portable information device illustrated in FIG. 1 is opened into ausage form.

FIG. 3 is a plan view schematically illustrating the internal structureof the portable information device illustrated in FIG. 2.

FIG. 4 is an enlarged perspective view of a principal portion in a statewhere a backbone member is omitted from the portable information deviceillustrated in FIG. 1.

FIG. 5 is an exploded perspective view of the backbone member.

FIG. 6A is a cross-sectional view schematically illustrating thecross-sectional structure along the VIA-VIA line in FIG. 1.

FIG. 6B is a cross-sectional view schematically illustrating thecross-sectional structure along the VIB-VIB line in FIG. 3.

FIG. 7A is a cross-sectional view schematically illustrating thecross-sectional structure along the VIIA-VIIA line in FIG. 1.

FIG. 7B is a cross-sectional view schematically illustrating thecross-sectional structure along the VIIB-VIIB line in FIG. 3.

FIG. 8 is a cross-sectional view schematically illustrating thecross-sectional structure along the VIII-VIII line in FIG. 2.

FIG. 9 is an enlarged perspective view of a principal portionillustrating the positional relationship between a display and a hingemechanism.

FIG. 10A is a side view schematically illustrating the positionalrelationship between the display and the hinge mechanism in a statewhere a pair of chassis members is opened.

FIG. 10B is a side view illustrating a state where the pair of chassismembers is operated so as to be closed from the state illustrated inFIG. 10A.

FIG. 10C is a side view illustrating a state where the pair of chassismembers is further operated so as to be closed from the stateillustrated in FIG. 10B.

FIG. 10D is a side view illustrating a state where the pair of chassismembers is further operated so as to be closed from the stateillustrated in FIG. 10C to be folded into a double-folded state.

FIG. 11 is a side view schematically illustrating the positionalrelationship between the display and the hinge mechanism in a statewhere the pair of chassis members is opened in a configuration having ahinge mechanism of a 3-shaft structure.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a preferable embodiment of a portable information deviceaccording to the present invention is described in detail with referenceto the attached drawings.

1. Description of Entire Configuration of Portable Information Device

FIG. 1 is a perspective view illustrating a state where a portableinformation device 10 according to one embodiment of the presentinvention is closed into a storage form. FIG. 2 is a perspective viewschematically illustrating a state where the portable information device10 illustrated in FIG. 1 is opened into a usage form. FIG. 3 is a planview schematically illustrating the internal structure of the portableinformation device 10 illustrated in FIG. 2.

As illustrated in FIG. 1 and FIG. 2, the portable information device 10has a first chassis member 12A, a second chassis member 12B, a backbonemember 14, and a display 16. This embodiment describes a tablet type PCwhich is foldable into a double-folded state like a book as an exampleof the portable information device 10. The portable information device10 may be a cellular phone, a smartphone, an electronic notebook, or thelike.

The chassis members 12A and 12B each are rectangular plate-like membersin which the side wall is formed so as to be raised on three sides otherthan the side corresponding to the backbone member 14. The chassismembers 12A and 12B each contain metal plates of stainless steel,magnesium, aluminum, and the like, fiber reinforced resin platescontaining reinforced fibers, such as carbon fibers, and the like, forexample. To the inner surface sides of the chassis members 12A and 12B,a display 16 is fixed through a support plate 18 (see also FIG. 6B). Thechassis members 12A and 12B are connected through a pair of hingemechanisms 19 and 19 provided in both end portions of the backbonemember 14. The hinge mechanisms 19 connect the chassis members 12A and12B so as to be foldable into the storage form illustrated in FIG. 1 andthe usage form illustrated in FIG. 2. A line C illustrated by the dashedline in FIG. 3 represents a bending center C serving as the center of afolding operation of the chassis members 12A and 12B.

In the chassis members 12A and 12B, inner end surfaces 12Aa and 12Ba onthe backbone member 14 side serve as hinge sides, and outer end surfaces12Ab and 12Bb on the side opposite to the backbone member 14 serve asopen end portion sides.

As illustrated in FIG. 3, a main substrate 20, a communication module21, a cooling fan 22, and the like are attached and fixed to the innersurface of the first chassis member 12A using a screw or the like whichis not illustrated. To the inner surface of the second chassis member12B, a sub-substrate 24, an antenna 25, a battery device 26, and thelike are attached and fixed using a screw or the like which is notillustrated. The main substrate 20 is an electronic substrate forperforming the overall control of the portable information device 10 andcarries various kinds of electronic components, such as a centralprocessing unit (CPU) and a memory which are not illustrated. Thecommunication module 21 is a device performing information processing ofvarious wireless communications of wireless LAN (Local Area Network) andthe like performing transmission and receiving with the antenna 25. Thecooling fan 22 is a fan for cooling heat generated in the centralprocessing unit and the like mounted on the main substrate 20. Thesub-substrate 24 is an electronic substrate functioning as a controllercontrolling the display state of the display 16. The battery device 26is a power supply of the portable information device 10 and can becharged from an external power supply through a power cable which is notillustrated.

The display 16 is a touch panel type liquid crystal display, forexample. The display 16 is structured so as to be foldable together withthe chassis members 12A and 12B when the chassis members 12A and 12B arefolded. The display 16 is a flexible display, such as an organic ELhaving a paper structure with high flexibility, for example and isopened/closed with an opening/closing operation of the chassis members12A and 12B.

The display 16 is attached and fixed to the inner surface sides of thechassis members 12A and 12B through the support plate 18 using a screwwhich is not illustrated. The rear surface of the display surface (frontsurface) of the display 16 is pasted and fixed to the surface of thesupport plate 18 using an adhesive, a double-sided tape, or the like. Inthe case of this embodiment, the support plate 18 has a pair of platemembers 18 a and 18 a which are disposed on the inner surface sides ofthe chassis members 12A and 12B and are connected to each other so as tobe bendable centering on the bending center C (see FIG. 6A and FIG. 6B).To the entire surface of the pair of plate members 18 a and 18 a, asheet-like member 18 b is stuck, whereby the pair of plate members 18 aand 18 a is connected to each other so as to be bendable.

The plate members 18 a contain metal plates of stainless steel,magnesium, aluminum, and the like, fiber reinforced resin plates inwhich a matrix resin containing a thermosetting resin or a thermoplasticresin is impregnated with reinforced fibers, such as carbon fibers, andthe like, for example. In this embodiment, a carbon fiber reinforcedresin plate containing carbon fibers as a reinforced resin is used. Thesheet-like member 18 b is a thin film containing a material havingflexibility, such as a thin resin film or metallic foil. The sheet-likemember 18 b is stuck to the entire surfaces of the plate members 18 aand 18 a. In this embodiment, metallic foil containing stainless steelis used as the sheet-like member 18 b. The display 16 is pasted to thesurface of the sheet-like member 18 b using an adhesive or the like. Inthe sheet-like member 18 b, a portion covering adjacent end portions ofthe plate members 18 a functions as a bending portion (flexible hinge)of the support plate 18.

In the support plates 18, the adjacent end surfaces of the pair of platemembers 18 a and 18 a abut on each other in the usage form in which thechassis members 12A and 12B are opened into a flat shape (see FIG. 6B).In the support plate 18, the adjacent end surfaces of the pair of platemembers 18 a and 18 a are separated from each other in the storage formin which the chassis members 12A and 12B are folded into a double-foldedstate (see FIG. 6A).

As illustrated in FIG. 2, a bezel member 27 is disposed on an outerperipheral edge portion of the surface of the display 16 in the state ofbeing attached and fixed to the inner surface sides of the chassismembers 12A and 12B (see also FIG. 8). The bezel member 27 is providedso as to cover a non-displaying region (inactive region) R2 of the outerperipheral edge portion excluding a display region (active region) R1 ofthe surface of the display 16.

Thus, the portable information device 10 can be configured so as to bechanged into the usage form illustrated in FIG. 1 and the storage formillustrated in FIG. 2 by opening/closing the display 16 provided on theinner side by opening/closing the pair of chassis members 12A and 12B.

Hereinafter, as illustrated in FIG. 1 to FIG. 3, the portableinformation device 10 is described designating a direction from thebackbone member 14 to the outer end surfaces 12Ab and 12Bb as an Xdirection and a direction along the longitudinal direction of thebackbone member 14 as a Y direction. With respect to the X direction, adirection from the backbone member 14 to the one outer end surface 12Abis sometimes referred to as an X1 direction and a direction from thebackbone member 14 to the other outer end surface 12Bb is sometimesreferred to as an X2 direction. Similarly, with respect to the Ydirection, a direction to one side (upper side in FIG. 3) in thelongitudinal direction of the backbone member 14 is sometimes referredto as a Y1 direction and a direction to the other side (lower side inFIG. 3) is sometimes referred to as a Y2 direction.

2. Description of Hinge Mechanism

An example of the configuration of the hinge mechanism 19 connecting thechassis members 12A and 12B is described. FIG. 4 is an enlargedperspective view of a principal portion in a state where the backbonemember 14 is omitted from the portable information device 10 illustratedin FIG. 1.

As illustrated in FIG. 3, the hinge mechanisms 19 each are disposed atpositions overlapping with both end portions in the longitudinaldirection of the backbone member 14. The hinge mechanisms 19 areprovided at positions located on the outside of the outer shape of thedisplay 16 and are linearly symmetrical with each other. The hingemechanism 19 has a first hinge chassis 28A, a second hinge chassis 28B,a first arm 30, and a second arm 31.

The first hinge chassis 28A is a part of a thin block shape formed ofresin, metal, or the like. The first hinge chassis 28A is fixed onto theinner surface of the first chassis member 12A using fixing screws 32.The second hinge chassis 28B is a part of a thin block shape formed ofresin, metal, or the like. The second hinge chassis 28B is fixed ontothe inner surface of the second chassis member 12B using the fixingscrews 32.

The first hinge chassis 28A has a recessed portion 34 on the rearsurface side landing on the inner surface of the first chassis member12A. The recessed portion 34 has a recessed shape which is opened fromthe inner side surface (side surface on the Y2 side in the hingemechanism 19 on the upper side in FIG. 3) of the first hinge chassis 28Ato the side surface (side surface on the X2 side) on the bending centerC side (also see FIG. 7A to FIG. 8). The second hinge chassis 28B has arecessed portion 35 on the rear surface side landing on the innersurface of the second chassis member 12B. The recessed portion 35 is arecessed shape which is opened from the inner side surface (side surfaceon the Y2 side in the hinge mechanism 19 of on the upper side in FIG. 3)of the second hinge chassis 28B to the side surface (side surface on theX1 side) on the bending center C side (also see FIG. 7A to FIG. 8). Therecessed portions 34 and 35 communicate with each other with the bendingcenter C interposed therebetween (see FIG. 3 and FIG. 7B).

While one end portion of the first arm 30 is rotatably connected to thefirst hinge chassis 28A through a first hinge shaft 36 a, the other endportion thereof is rotatably connected to the second hinge chassis 28Bthrough a second hinge shaft 36 b (also see FIG. 7A and FIG. 7B). Whileone end portion of the second arm 31 is rotatably connected to thesecond hinge chassis 28B through a third hinge shaft 36 c, the other endportion is rotatably connected to the first hinge chassis 28A through afourth hinge shaft 36 d (also see FIG. 7A and FIG. 7B).

The first arm 30 and the second arm 31 are arranged in parallel in the Ydirection. The second hinge shaft 36 b of the first arm 30 is located ata position between the third hinge shaft 36 c and the fourth hinge shaft36 d of the second arm 31. The third hinge shaft 36 c of the second arm31 is located at a position between the first hinge shaft 36 a and thesecond hinge shaft 36 b of the first arm 30. Thus, the first arm 30 andthe second arm 31 are alternately arranged side by side with apositional shift in the X direction and the Y direction.

In each hinge mechanism 19, when the chassis members 12A and 12B arefolded centering on the bending center C, the arm members 30 and 31rotate through the hinge shafts 36 a to 36 d (see FIG. 4). Thus, thehinge mechanisms 19 connect the chassis members 12A and 12B so as to berotatable from the state in which the chassis members 12A and 12B arefolded into a double-folded state to the state in which the chassismembers 12A and 12B are opened into a flat shape.

3. Description of Backbone Member

The backbone member 14 is described. In the storage form illustrated inFIG. 1, inner end surfaces 12Aa and 12Ba of the chassis members 12A and12B are greatly separated from each other to generate a gap (also seeFIG. 4). Then, in the portable information device 10, the backbonemember 14 is provided in order to prevent the display 16 and theelements, such as the main substrate 20 and the battery device 26, frombeing exposed by covering the gap. FIG. 5 is an exploded perspectiveview of the backbone member 14. FIG. 6A is a cross-sectional viewschematically illustrating the cross-sectional structure along theVIA-VIA line in FIG. 1. FIG. 6B is a cross-sectional view schematicallyillustrating the cross-sectional structure along the VIB-VIB line inFIG. 3.

The backbone member 14 is a thin plate-like member having flexibilityserving as the backbone in folding the portable information device 10.The backbone member 14 is provided throughout and between the chassismembers 12A and 12B so as to cover the inner end surfaces 12Aa and 12Bafrom the inner side while crossing the same (see FIG. 3, FIG. 6A, andFIG. 6B).

As illustrated in FIG. 5, the backbone member 14 has a sheet-like member(flexible sheet-like member) 40, a first support member 42, a secondsupport member 43, and a plurality of reinforcing members 44 a, 44 b, 44c, and 44 d.

The first support member 42 and the second support member 43 are thinplate-like members extending in the longitudinal direction (Y direction)of the backbone member 14. The reinforcing members 44 a to 44 d are thinplate-like members extending in the longitudinal direction of thebackbone member 14 and are narrower in the X direction than the supportmembers 42 and 43. The reinforcing members 44 a to 44 d are arrangedside by side in the X2 direction from the first chassis member 12A tothe second chassis member 12B between the support members 42 and 43. Thefirst support member 42, the second support member 43, and thereinforcing members 44 a to 44 d are thin plate members formed of resin,metal, and the like.

The sheet-like member 40 is a fiber reinforced resin plate in which athermosetting resin, such as epoxy resin, is impregnated with reinforcedfibers, such as carbon fibers. The sheet-like member 40 is a thinsheet-like member of 0.3 mm or less, for example, and has flexibilityand high strength. As the reinforced fibers, various materials, such asmetal fibers, such as stainless steel fibers, and inorganic fibers, suchas glass fibers, may be used. The sheet-like member 40 may be formed ofa resin film, metallic foil, and the like.

The support members 42 and 43 and the reinforcing members 44 a to 44 dare stuck to the surface of the sheet-like member 40 using an adhesive,a double-sided tape, or the like. The support members 42 and 43 and thereinforcing members 44 a to 44 d and the sheet-like members 40 may beintegrally formed. Thus, the backbone member 14 is bendable inconnection with a folding operation of the chassis members 12A and 12B.In the sheet-like member 40, a portion covering the inner end surfaces12Aa and 12Ba of the chassis members 12A and 12B serves as a bendingportion 40 a (see FIG. 6A and FIG. 6B). The sheet-like member 40 has aplurality of notch portions 40 b arranged side by side in the Ydirection in an edge portion on the second support member 43 side.

The first support member 42 is provided slidably in the X directioncrossing the chassis members 12A and 12B along the inner surface of thefirst chassis member 12A on the inner surface side. The first supportmember 42 has pressing surfaces 42 a on the surfaces in both endportions in the longitudinal direction. The pressing surface 42 a is asurface one step lower than the other surfaces of the first supportmember 42. The first support member 42 has a plurality of grooveportions 42 b in the X direction in the surface of a portion locatedbetween the pair of pressing surfaces 42 a and 42 a in the longitudinaldirection. A side surface 42 c on the X2 side facing the reinforcingmember 44 a of the first support member 42 forms an inclined surfaceretreating in the X1 direction from the reinforcing member 44 a side ina direction from the rear surface side (sheet-like member 40 side) tothe front surface side (see FIG. 6A and FIG. 6B).

The first support member 42 receives energization force by a tensionspring (elastic member) 45 along the X direction (see FIG. 3 and FIG.6A). The tension spring 45 always energizes the backbone member 14 alongthe X1 direction in a direction from the second chassis member 12B tothe first chassis member 12A.

The second support member 43 is non-slidably attached and fixed to theinner surface of the second chassis member 12B on the inner surface sideusing a fixing screw 46 (see FIG. 6A and FIG. 6B). The second supportmember 43 has pressing surfaces 43 a on the surfaces in both endportions in the longitudinal direction. The pressing surface 43 a is asurface one step lower than the other surfaces of the second supportmember 43. The second support member 43 has a plurality of grooveportions 43 b in the X direction in the surface of a portion locatedbetween the pair of pressing surfaces 43 a and 43 a. Through-holes 47for passing screw portions of the fixing screws 46 are provided atappropriate positions in the longitudinal direction of the secondsupport member 43. The fixing screws 46 are fastened and fixed to thesecond chassis member 12B through the notch portions 40 b of thesheet-like member 40. A side surface 43 c on the X1 side facing thereinforcing member 44 d of the second support member 43 forms aninclined surface retreating in the X2 direction from the reinforcingmember 44 d side in a direction from the rear surface side (sheet-likemember 40 side) to the front surface side (see FIG. 6A and FIG. 6B).

Each of the reinforcing members 44 a to 44 d has a trapezoidalcross-sectional shape in which the upper bottom and the lower bottom aresomewhat curved. A pressing surface 44 e which is a surface one steplower than the other surfaces is provided on the surfaces in both endportions in the longitudinal direction of each of the reinforcingmembers 44 a to 44 d (see FIG. 5). Each of the pressing surfaces 44 e isformed at substantially the same height as that of the pressing surfaces42 a and 43 a of the support member 42 and 43 (see FIG. 7B). The numberof the reinforcing members 44 a to 44 d can be changed as appropriate.

Each of the reinforcing members 44 a to 44 d has a side surface 48 a onthe first support member 42 side (X1 side) and a side surface 48 b onthe second support member side (X2 side) (see FIG. 6A and FIG. 6B). Thetwo reinforcing members 44 a and 44 b close to the first support member42 side and the two reinforcing members 44 c and 44 d close to thesecond support member 43 side are substantially linearly symmetricalwith each other about the boundary between the reinforcing members 44 band 44 c at the center. The side surface 48 a of the reinforcing member44 a forms an inclined surface retreating in the X2 direction from thefirst support member 42 side in a direction from the rear surface side(sheet-like member 40 side) to the front surface side. The side surface48 b of the reinforcing member 44 d forms an inclined surface retreatingin the X1 direction from the second support member 43 side in adirection from the rear surface side (sheet-like member 40 side) to thefront surface side. The other side surfaces 48 a and 48 b face thefacing side surfaces 48 b and 48 a, respectively, substantially inparallel to each other or form an inclined surface in a direction ofsomewhat separating from each other.

In the storage form illustrated in FIG. 6A, the side surfaces 48 a and48 b of the reinforcing members 44 a to 44 d abut on each other on theinner surface side of the bending portion 40 a of the sheet-like member40 bent into a double-folded state to form an arch shape (arc shape)similar to a shape in which a plurality of teeth are arranged side byside without a gap. Herein, the side surfaces 48 a and 48 b of thereinforcing members 44 a and 44 d in both ends abut on the side surfaces42 c and 43 c of the support member 42 and 43, respectively. Due to thearch shape, the inner end surfaces 12Aa and 12Ba are separated from eachother, so that the reinforcing members 44 a to 44 d function as supportsfirmly supporting the chassis members 12A and 12B in the storage formwith reduced rigidity. More specifically, in the vicinity of thebackbone member 14 between the chassis members 12A and 12B, the hingemechanisms 19 are provided in both end portions in the Y direction inthe storage form but, in portions other than the both end portions, aportion having no rigidity extends in the Y direction. In the portableinformation device 10, the support members 42 and 43 and the reinforcingmembers 44 a to 44 b form supports of an arch shape extending in the Ydirection to secure the rigidity in the thickness direction in thestorage form.

In such a storage form, the inner end surfaces 12Aa and 12Ba of thechassis members 12A and 12B are disposed at the most separatedpositions. Therefore, the backbone member 14 is positioned at aretreated position where the first support member 42 side which is theslide side is drawn to the most inner end surface 12Aa side (X2direction) on the inner surface of the first chassis member 12A. Herein,the first support member 42 slides to the inner end surface 12Aa sideagainst the energization force of the tension spring 45.

On the other hand, in the usage form in which the chassis members 12Aand 12B are opened into a flat shape, the reinforcing members 44 a to 44d are disposed side by side in one row together with the support members42 and 43 on the inner surfaces of the chassis members 12A and 12B.Therefore, the backbone member 14 takes a form of a flat shape havingthe minimum thickness. In the usage form, the inner end surfaces 12Aa ofthe chassis members 12A and 12B and 12Ba are disposed at positions wherethe inner end surfaces 12Aa are most close to or abut on each other.Therefore, the backbone member 14 is located at an advance positionwhere the first support member 42 side which is the slide side advancesto the outer end surface 12Ab side (X1 direction) opposite to the mostinner end surface 12Aa side on the inner surface of the first chassismember 12A. Herein, the first support member 42 smoothly slides to theouter end surface 12Ab side by the energization force of the tensionspring 45, and therefore the backbone member 14 does not cause floatingor catching in sliding.

A wiring line 49 connecting the main substrate 20 and the sub-substrate24, for example, is passed through the groove portions 42 b and 43 bcrossing the chassis member 12A and 12B on the right side and the leftside. Upper openings of the groove portions 42 b and 43 b are coveredwith a lid member 51 (see FIG. 6A). The lid member 51 is a thin filmcontaining materials having flexibility, such as a thin resin film ormetallic foil. The lid member 51 is provided over substantially theentire length excluding both end portions in the Y direction of thebackbone member 14 and over the entire width in the X direction thereofand is pasted to the surface of the backbone member 14. In the case ofthis embodiment, a sheet-like member containing stainless steel(stainless steel sheet) is used for the lid member 51. An end portion onthe X2 side of the lid member 51 is stuck to the surface of the secondsupport member 43 and an end portion on the X1 side thereof is movablyplaced on the surface of the first support member 42, for example (seeFIG. 6A and FIG. 6B). Therefore, the lid member 51 prevents the fallingoff of the wiring lines 49 from the groove portions 42 b and 43 b whilesliding on the backbone member 14 following the slide of the backbonemember 14. Therefore, the wiring lines 49 can be prevented from floatingfrom the upper openings of the groove portions 42 b and 43 b and fallingoff on the outside of the groove portions 42 b and 43 b. Thus, in theportable information device 10, the lid member 51 containing metallicfoil closes the groove portions 42 b and 43 b to prevent falling off ofthe wiring lines 49. Therefore, when the portable information device 10is changed from the storage form illustrated in FIG. 6A to the usageform illustrated in FIG. 6B, for example, the lid member 51 is also benttogether with the backbone member 14 so as to follow the bendingoperation of the pair of plate members 18 a and 18 a of the supportplate 18. As a result, the wiring lines 49 can be certainly preventedfrom contacting adjacent end portions (edge) between the plate members18 a and 18 a and the like, so that the durability and the reliabilityof the portable information device 10 are improved. The end portion onthe X1 side which is the end portion on the slide side of the lid member51 may be configured so as to extend beyond the end portion on the X1side of the first support member 42. Thus, the wiring lines 49 can beprotected in a region larger than a region where the wiring lines 49overlap with the backbone member 14.

4. Description of Relationship between Backbone Member and HingeMechanism

The relationship between the backbone member 14 and the hinge mechanism19 is described. FIG. 7A is a cross-sectional view schematicallyillustrating the cross-sectional structure along the VIIA-VIIA line inFIG. 1. FIG. 7B is a cross-sectional view schematically illustrating thecross-sectional structure along the VIIB-VIIB line in FIG. 3. FIG. 8 isa cross-sectional view schematically illustrating the cross-sectionalstructure along the VIII-VIII line in FIG. 2.

As illustrated in FIG. 1 and FIG. 4, the backbone member 14 extends to aposition where the backbone member covers the rear surface side of eachof the hinge mechanisms 19 to prevent the hinge mechanisms 19 fromexposing from between the inner end surfaces 12Aa and 12Ba of thechassis members 12A and 12B.

As illustrated in FIG. 3, FIG. 7A, FIG. 7B, and FIG. 8, the pressingsurfaces 42 a, 43 a, and 44 e in both end portions in the longitudinaldirection of the backbone member 14 are held between the rear surfacesof the hinge chassis 28A and 28B and the inner surfaces of the chassismembers 12A and 12B. Specifically, the pressing surfaces 42 a, 43 a, and44 e of the backbone member 14 are inserted and disposed in the recessedportions 34 and 35 of the hinge chassis 28A and 28B. Herein, at leastthe pressing surfaces 42 a and 44 e of the first support member 42 andthe reinforcing members 44 a to 44 d are slidably held within therecessed portion 34 of the first support member 42, and are guidedbetween the inner surface of the first chassis 12A and the top surfaceof the recessed portion 34. More specifically, the recessed portion 34on the first hinge chassis 28A side guides the backbone member 14 so asto be slidable in the X direction and prevents floating or the like insliding. The recessed portion 34 has a length dimension capable ofcoping with a slide distance (slide range) (see FIG. 7A) L of thebackbone member 14. Therefore, the recessed portion 34 is longer in theX direction than the recessed portion 35 on the second hinge chassis 28Bside.

As illustrated in FIG. 8, the hinge mechanisms 19 each have anengagement protruding portion 50 in the outer surface of each of thehinge chassis 28A and 28B. On the other hand, engagement recessedportions 52 a are formed in the internal surfaces of wall portions 52which are the side walls along the X direction raised from the innersurfaces of the chassis members 12A and 12B facing the engagementprotruding portions 50. The engagement recessed portion 52 a allows theengagement of the engagement protruding portion 50 and regulates atleast the movement in a direction where the engagement protrudingportion 50 raises from the inner surfaces of the chassis members 12A and12B.

Therefore, the first hinge chassis 28A is held between the inner surfaceof the first chassis member 12A and the top surface of the engagementrecessed portion 52 a of the wall portion 52 to be prevented fromfloating. The second hinge chassis 28B is held between the inner surfaceof the second chassis member 12B and the top surface of the engagementrecessed portion 52 a of the wall portion 52 to be prevented fromfloating. More specifically, the hinge chassis 28A and 28B are providedwith the recessed portions 34 and 35 into which the backbone member 14is inserted on the rear surface sides, and therefore the fixing screws32 can be fastened only around the recessed portions 34 and 35.Therefore, there is a concern that the hinge chassis 28A and 28B causefloating in the movement of the hinge mechanisms 19. Thus, in theportable information device 10, the hinge chassis 28A and 28B areengaged with and pressed against the wall portions 52 of the chassismembers 12A and 12B to prevent the hinge chassis 28A and 28B fromfloating. The hinge chassis 28A and 28B may be engaged with theengagement recessed portion 52 a without providing the engagementprotruding portions 50.

5. Description of Positional Relationship Between Display and HingeMechanism

The positional relationship between the display 16 and the hingemechanism 19 is described. FIG. 9 is an enlarged perspective view of aprincipal portion illustrating the positional relationship between thedisplay 16 and the hinge mechanism 19. FIG. 10A to FIG. 10D are sideoperation views schematically illustrating the positional relationshipbetween the display 16 and the hinge mechanism 19 when the pair ofchassis members 12A and 12B is rotated from the opened state to theclosed state. In FIG. 10A to FIG. 10D, the elements, such as thebackbone member 14, are omitted in consideration of ease of viewing, andthe second arm 31 and the hinge axes 36 c and 36 d are illustrated bythe dashed lines.

First, the display 16 is attached and fixed to the chassis members 12Aand 12B through the support plate 18 as first described above. The hingemechanism 19 is disposed at each of both end portions in thelongitudinal direction (Y direction) of the one edge portions (inner endsurfaces 12Aa and 12Ba) of the chassis member 12A and 12B and isprovided at a position located on the outside of the outer shape of thedisplay 16.

The attachment structure of the display 16 is not limited and, forexample, the chassis members 12A and 12B are positioned and fixedthrough attachment pieces 18 c of the support plate 18 as illustrated inFIG. 3. The attachment pieces 18 c are provided at appropriate positionsof an outer peripheral edge portion of the support plate 18 and areprojection pieces projecting outwardly from an outer peripheral edgeportion of the plate member 18 a. In the attachment pieces 18 c,screwing through-holes are formed in the center. The support plate 18(display 16) is fastened and fixed to the chassis members 12A and 12B byfastening fixing screws 54 to the chassis members 12A and 12B.

The display 16 is folded into a double-folded state. Therefore, thesupport plate 18 (display 16) is not provided with the attachment pieces18 c at a position corresponding to the bending portion 40 a of thebackbone member 14. More specifically, the display 16 is not fixed tothe chassis members 12A and 12B in a bending region R3 (see FIG. 3 andFIG. 6A) which is a portion corresponding to the backbone member 14, andis fixed and positioned in portions other than the bending region R3. Inplace of the attachment pieces 18 c, a boss-like female screw portionand the like may be provided in the undersurface of the plate member 18a, for example.

Thus, the portable information device 10 is folded into a double-foldedstate in the state where the display 16 is positioned and fixed to thechassis members 12A and 12B. Therefore, depending on the positionalrelationship between the display 16 and the hinge shafts 36 a to 36 d ofthe hinge mechanisms 19, a load to the bending region R3 of the display16 increases in an opening/closing operation, so that smooth bending ofthe display 16 may be disabled.

Then, the portable information device 10 is configured so that thesurface 16 a of the display 16 and axial centers A1 to A4 of the hingeshafts 36 a to 36 d are disposed on the same plane in the state wherethe first chassis member 12A and the second chassis member 12B areopened into a flat shape (usage form) as illustrated in FIG. 10A. Inother words, the axial centers A1 to A4 are disposed on a virtual planein agreement with the surface 16 a of the display 16 in the state ofbeing opened into a flat shape. Thus, when the chassis members 12A and12B are operated so as to be folded from the usage form illustrated inFIG. 10A, the arms 30 and 31 rotate around the hinge shafts 36 a to 36d, so that the chassis members 12A and 12B are gradually folded and thedisplay 16 is also bent as illustrated in FIG. 10B and FIG. 10C.Finally, the chassis members 12A and 12B are folded into thedouble-folded state and the display 16 is also folded into adouble-folded state drawing an arc of a predetermined curvature asillustrated in FIG. 10D.

The configuration in which the axial centers A1 to A4 of the hingeshafts 36 a to 36 d and the surface 16 a of the display 16 are alignedwith each other is applicable also to hinge mechanisms of a 3-shaftstructure or 5 or more-shaft structures besides the 4-shaft structure.For example, a hinge mechanism 56 illustrated in FIG. 11 has aconfiguration in which the first arm 30 is connected to the first hingeshaft 36 a and a fifth hinge shaft 36 e, and the second arm 31 isconnected to the fourth hinge shaft 36 d and the fifth hinge shaft 36 e.More specifically, the hinge mechanism 56 has a 3-shaft structure inwhich the fifth hinge shaft 36 e is shared with the arms 30 and 31. Alsoin this hinge mechanism 56, a smooth bending operation of the display 16is enabled by disposing the axial centers A1, A4, and A5 of the hingeshafts 36 a, 36 d, and 36 e and the surface 16 a of the display 16 onthe same plane.

6. Description of Operational Effects of Portable Information Device

As described above, the portable information device according to thisembodiment has the first chassis member 12A and the second chassismember 12B which are foldable into a double-folded state by connectionof one edge portions (edge portions on the sides of the inner endsurfaces 12Aa and 12Ba) disposed adjacent to each other by the hingemechanisms 19 and the display 16 which is provided over the innersurfaces of the first chassis member 12A and the second chassis member12B and which is foldable into a double-folded state. The portableinformation device 10 has the backbone member 14 provided throughoutbetween the inner surface of the one edge portion of the first chassismember 12A and the inner surface of the one edge portion of the secondchassis member 12B so as to cover a gap between the one edge portion ofthe first chassis member 12A and the one edge portion of the secondchassis member 12B connected by the hinge mechanisms 19. The backbonemember 14 is held between the inner surfaces of the first chassis member12A and the second chassis member 12B, and the rear surfaces of thehinge mechanisms 19 disposed on the inner surfaces and is slidablyprovided between the inner surface of at least one of the first chassismember 12A and the second chassis member 12B and the rear surface of thehinge mechanism 19 disposed on the inner surface of the at least one ofthe first chassis member 12A and the second chassis member 12B.

Therefore, even when the two chassis members 12A and 12B are folded intoa double-folded state, the backbone member 14 can prevent the hingemechanisms 19 from being exposed together with the internal elements,such as the main substrate 20, from the gap between the chassis member12A and 12B, and can secure the appearance quality or the durability ofproducts. Moreover, the backbone member 14 is slidably provided betweenthe inner surface of at least one of the chassis member 12A and 12B andthe rear surfaces of the hinge mechanisms 19. Thus, the backbone member14 smoothly slides following an opening/closing operation of the firstchassis member 12A and the second chassis member 12B without causingfloating or the like. Therefore, when the two chassis members 12A and12B are opened into a flat shape, so that a gap therebetween decreases,the back bone member 14 can be prevented from causing floating, apositional shift, or the like within the chassis members 12A and 12B.

The hinge mechanism 19 has the first hinge chassis 28A fixed on theinner surface of the first chassis member 12A, the second hinge chassis28B fixed on the inner surface of the second chassis member 12B, and thehinge shafts 36 a to 36 d rotatably connecting the first hinge chassis28A and the second hinge chassis 28B, the first hinge chassis 28A andthe second hinge chassis 28B each have recessed portions 34 and 35communicating with each other on the rear surface sides thereof, and thebackbone member 14 is disposed in the recessed portions 34 and 35. Thus,the backbone member 14 is certainly slidably held in the recessedportions 34 and 35 provided in the rear surface sides of the hingechassis 28A and 28B and can more certainly prevent floating, apositional shift, or the like thereof.

The first hinge chassis 28A is held between the inner surface of thefirst chassis member 12A and the wall portion 52 raised from the innersurface of the first chassis member 12A and the second hinge chassis 28Bis held between the inner surface of the second chassis member 12B andthe wall portion 52 raised from the inner surface of the second chassismember 12B. As described above, the hinge chassis 28A and 28B have therecessed portions 34 and for holding the backbone member 14,respectively. Therefore, the fixing screws 32 can be fastened only atpositions avoiding the recessed portions 34 and 35. Then, in theportable information device 10, the chassis members 12A and 12B areengaged with and pressed against the wall portions 52 of the hingechassis 28A and 28B to prevent floating or rattling in operations.

The hinge mechanism 19 is disposed at each of both end portions in thelongitudinal direction of one edge portions of the first chassis member12A and the second chassis member 12B. The wall portions 52 of the firsthinge chassis 28A and the second hinge chassis 28B each form the sidewalls of the portable information device 10, and the first hinge chassis28A and the second hinge chassis 28B are engaged with the recessedportions 52 a formed in the inner wall surfaces of the wall portions 52.Thus, the hinge chassis 28A and 28B can be more firmly fixed.

In the portable information device 10, the hinge mechanism 19 isdisposed at each of both end portions in the longitudinal direction ofthe one edge portions of the first chassis member 12A and the secondchassis member 12B, and the hinge mechanisms 19 are provided at thepositions located on the outside of the outer shape of the display 16.Each of the hinge mechanisms 19 has the first hinge chassis 28A fixed onthe inner surface of the first chassis member 12A, the second hingechassis 28B fixed on the inner surface of the second chassis member 12B,and the hinge shafts 36 a to 36 d rotatably connecting the first hingechassis 28A and the second hinge chassis 28B. At least portions otherthan bending region R3 corresponding to the backbone member 14 of thedisplay 16 are positioned and fixed to the first chassis member 12A andthe second chassis member 12B. The surface 16 a of the display 16 andthe axial centers A1 to A4 of the hinge shafts 36 a to 36 d are disposedon the same plane in the usage form in which the first chassis member12A and the second chassis member 12B are opened into a flat shape.

Therefore, in the operation of folding the chassis members 12A and 12B,which are opened into a flat shape, into a double-folded state, thedisplay 16 is smoothly folded into a double-folded state following therotation operation of the hinge mechanisms 19, in spite of theperipheral length difference. This prevents the application of anexcessive load to the display 16 in opening/closing of the chassismembers 12A and 12B and causing floating or defects. More specifically,in the configuration examples illustrated in FIG. 10A to FIG. 10D, forexample, the surface 16 a of the display 16 in the state illustrated inFIG. 10A is folded without involving the movement of a central portionbetween the hinge shafts 36 b and 36 c at the center in the bendingoperation illustrated in FIG. 10A to FIG. 10D. Thus, the display 16 canperform a smooth bending operation along the bending track whendesigning the same.

It is a matter of course that the present invention is not limited tothe embodiments described above and can be freely altered withoutdeviating from the scope of the present invention.

One edge side of the backbone member 14 may be slidably held by thesecond chassis member 12B and the other edge side thereof may be fixedto the first chassis member 12A. Moreover, the backbone member 14 may beslidably held by each of the chassis members 12A and 12B.

We claim:
 1. A portable information device comprising: a first chassismember and a second chassis member foldably connected by connection ofone edge portions disposed adjacent to each other by a hinge mechanism;a display over inner surfaces of the first chassis member and the secondchassis member and which is foldable into a double-folded state; and abackbone member throughout and between the inner surface of the one edgeportion of the first chassis member and the inner surface of the oneedge portion of the second chassis member so as to cover a gap betweenthe one edge portion of the first chassis member and the one edgeportion of the second chassis member connected by the hinge mechanism,wherein the backbone member is held between the inner surfaces of thefirst chassis member and the second chassis member, and rear surfaces ofthe hinge mechanisms disposed on the inner surfaces, and is slidablyprovided between the inner surface of at least one of the first chassismember and the second chassis member and a rear surface of the hingemechanism disposed on the inner surface of the at least one of the firstchassis member and the second chassis member, wherein: the hingemechanism has a first hinge chassis fixed on the inner surface of thefirst chassis member, a second hinge chassis fixed on the inner surfaceof the second chassis member, and a hinge shaft rotatably connecting thefirst hinge chassis and the second hinge chassis, the first hingechassis and the second hinge chassis each have a recessed portioncommunicating with each other on rear surface sides thereof, and thebackbone member is disposed in the recessed portions.
 2. The portableinformation device according to claim 1, wherein: the backbone member ison the inner surface of the one edge portion of the first chassis memberso as to be slidable in a direction from the second chassis member tothe first chassis member along the inner surface, and is non-slidablyfixed to the inner surface of the one edge portion of the second chassismember, and the recessed portion of the first hinge chassis extends overa slide range of the backbone member.
 3. The portable information deviceaccording to claim 1, wherein: the hinge mechanism is at each of bothend portions in a longitudinal direction of the one edge portions in thefirst chassis member and the second chassis member.
 4. The portableinformation device according to claim 1, wherein: the first hingechassis is held between an inner surface of the first chassis member anda wall portion raised from the inner surface of the first chassismember, and the second hinge chassis is held between an inner surface ofthe second chassis member and a wall portion raised from the innersurface of the second chassis member.
 5. The portable information deviceaccording to claim 4, wherein: the hinge mechanism is at each of bothend portions in the longitudinal direction of the one edge portions inthe first chassis member and the second chassis member, the wallportions of the first hinge chassis and the second hinge chassis eachform side walls of the portable information device, and the first hingechassis and the second hinge chassis are engaged with the recessedportions formed in inner wall surfaces of the wall portions.
 6. Theportable information device according to claim 1, wherein: the hingemechanism is at each of both end portions in a longitudinal direction ofthe one edge portions in the first chassis member and the second chassismember, each hinge mechanism is at a position located on an outside ofan outer shape of the display, at least a portion other than a bendingregion corresponding to the backbone member of the display is positionedand fixed to the first chassis member and the second chassis member, anda surface of the display and an axial center of the hinge shaft aredisposed on a same plane in a state where the first chassis member andthe second chassis member are opened into a flat shape.
 7. A portableinformation device comprising: a first chassis member and a secondchassis member foldably connected by connection of one edge portionsdisposed adjacent to each other by a hinge mechanism; and a display overinner surfaces of the first chassis member and the second chassis memberand which is foldable into a double-folded state, wherein: the hingemechanism is at each of both end portions in a longitudinal direction ofthe one edge portions in the first chassis member and the second chassismember, each hinge mechanism is at a position located on an outside ofan outer shape of the display, each hinge mechanism has a first hingechassis fixed on the inner surface of the first chassis member, a secondhinge chassis fixed on the inner surface of the second chassis member,and a hinge shaft rotatably connecting the first hinge chassis and thesecond hinge chassis, the display is positioned and fixed to the firstchassis member and the second chassis member, and a surface of thedisplay and an axial center of the hinge shaft are disposed on a sameplane in a state where the first chassis member and the second chassismember are opened into a flat shape, wherein: each hinge mechanism has afirst arm, one end portion of which is rotatably connected to the firsthinge chassis through a first hinge shaft and another end portion ofwhich is rotatably connected to the second hinge chassis through asecond hinge shaft; and a second arm, one end portion of which isrotatably connected to the second hinge chassis through a third hingeshaft and another end portion of which is rotatably connected to thefirst hinge chassis through a fourth hinge shaft, and the surface of thedisplay and axial centers of the first hinge shaft, the second hingeshaft, the third hinge shaft, and the fourth hinge shaft are disposed ona same plane in a state where the first chassis member and the secondchassis member are opened into the flat shape.
 8. A portable informationdevice comprising: a first chassis member and a second chassis memberfoldably connected by connection of one edge portions disposed adjacentto each other by a hinge mechanism; a display over inner surfaces of thefirst chassis member and the second chassis member and which is foldableinto a double-folded state; and a backbone member throughout and betweenthe inner surface of the one edge portion of the first chassis memberand the inner surface of the one edge portion of the second chassismember so as to cover a gap between the one edge portion of the firstchassis member and the one edge portion of the second chassis memberconnected by the hinge mechanism, wherein the backbone member is heldbetween the inner surfaces of the first chassis member and the secondchassis member, and rear surfaces of the hinge mechanisms disposed onthe inner surfaces, and is slidably provided between the inner surfaceof at least one of the first chassis member and the second chassismember and a rear surface of the hinge mechanism disposed on the innersurface of the at least one of the first chassis member and the secondchassis member, wherein: the hinge mechanism is at each of both endportions in a longitudinal direction of the one edge portions in thefirst chassis member and the second chassis member, each hinge mechanismis at a position located on an outside of an outer shape of the display,each hinge mechanism has a first hinge chassis fixed on the innersurface of the first chassis member, a second hinge chassis fixed on theinner surface of the second chassis member, and a hinge shaft rotatablyconnecting the first hinge chassis and the second hinge chassis, atleast a portion other than a bending region corresponding to thebackbone member of the display is positioned and fixed to the firstchassis member and the second chassis member, a surface of the displayand an axial center of the hinge shaft are disposed on a same plane in astate where the first chassis member and the second chassis member areopened into a flat shape, each hinge mechanism has a first arm, one endportion of which is rotatably connected to the first hinge chassisthrough a first hinge shaft and another end portion of which isrotatably connected to the second hinge chassis through a second hingeshaft; and a second arm, one end portion of which is rotatably connectedto the second hinge chassis through a third hinge shaft and another endportion of which is rotatably connected to the first hinge chassisthrough a fourth hinge shaft, and the surface of the display and axialcenters of the first hinge shaft, the second hinge shaft, the thirdhinge shaft, and the fourth hinge shaft are disposed on a same plane ina state where the first chassis member and the second chassis member areopened into the flat shape.